sandman Posted August 1, 2017 Report Posted August 1, 2017 Does anyone have any experience using dewaxed shellac as a ground? Specifically under an oil varnish such as joha Italian oil?
Don Noon Posted August 2, 2017 Report Posted August 2, 2017 I used it on some of my early instruments. It was OK, but I think it gave a washed-out look, particularly on the maple.
Michael_Molnar Posted August 2, 2017 Report Posted August 2, 2017 I got nice results when I applied it as a heavy paste, but Brandmair told me that she did not detect it on Cremonese instruments.
Nick Allen Posted August 2, 2017 Report Posted August 2, 2017 I tried it on test pieces. I thought it gave it a weird candy coating kind of look under varnish. You may want to try pumice/mica/some other mineral mixed with clear varnish as a ground coat. I say that because I'm in your exact situation too! I did it and it came out much softer and transparent. But that's just my limited experience.
MikeC Posted August 2, 2017 Report Posted August 2, 2017 20 minutes ago, Michael_Molnar said: I got nice results when I applied it as a heavy paste, but Brandmair told me that she did not detect it on Cremonese instruments. They did not detect it even as an over coat of polish? I thought they all had polish on them and at least one component of that would probably be shellac. And how do you make a heavy paste of shellac?
Matthew Hannafin Posted August 2, 2017 Report Posted August 2, 2017 I agree with Don. It's easy to use, and friendly for creating even color, but it doesn't really look brilliant on the maple. One of the biggest challenges I've found is getting some color into the spruce, but avoid uneven color, and especially burning of grain. I'm still using shellac to try and evenly size the belly (I go back and forth between very thin shellac and diluted hide glue). I still use a bit of shellac on the maple bits as well. I'm using plaster of paris, sugar stain, and then a rub with a pumice & thick shellac mix (until the desired texture is achieved and ready for color varnish.) ~Matt
Jim Bress Posted August 2, 2017 Report Posted August 2, 2017 For #2 on recommendation from someone that actually knows what he's doing, I did a rub coat size with thin dewaxed stick lac (28 g stick lac/ 240 ml ethanol) with no sealer on the top. I had to thin the stick lac that far to get a rub coat on without having a blotchy top. I followed that with two brush coats of the same stick lac colored with a bit of catechu to counter the slight green ting to my oil varnish that I put on over the ground. -Jim
Michael_Molnar Posted August 2, 2017 Report Posted August 2, 2017 1 hour ago, MikeC said: They did not detect it even as an over coat of polish? I thought they all had polish on them and at least one component of that would probably be shellac. And how do you make a heavy paste of shellac? Mike, You are changing the focus. The issue was using shellac as a ground, not French polishing.
Mike Spencer Posted August 2, 2017 Report Posted August 2, 2017 Sandman is this your first instrument that you are getting ready to varnish? If it is then I'd suggest going with something that is easy like the gelatin size or shellac. It will work just fine and you won't have to drive yourself crazy with all the possibilities.
MikeC Posted August 2, 2017 Report Posted August 2, 2017 39 minutes ago, Michael_Molnar said: Mike, You are changing the focus. The issue was using shellac as a ground, not French polishing. Hi Michael, I understand that, but you said Brandmair didn't detect it so I thought you meant that they didn't detect it at all which surprises me. So maybe they did detect some but just not in the ground layers? I don't have the book so I don't know all their findings.
ctanzio Posted August 2, 2017 Report Posted August 2, 2017 I've used diluted dewaxed shellac as a ground under oil varnishes. Does a great job of sealing the wood. If you get inconsistent coloring then the mixture is not dilute enough. Make sure it is truly dewaxed shellac to get the highest clarity. Oil varnishes tend to want to form a "mechanical" bond to a surface, so you might have to gently sand the shellac coat with around 600 grit before the first oil varnish coat. Alternatively, if you first applied a mineral ground, then a light coat of thin shellac to seal it will normally still allow enough bite for the oil varnish.
Michael_Molnar Posted August 2, 2017 Report Posted August 2, 2017 4 hours ago, MikeC said: Hi Michael, I understand that, but you said Brandmair didn't detect it so I thought you meant that they didn't detect it at all which surprises me. So maybe they did detect some but just not in the ground layers? I don't have the book so I don't know all their findings. I doubt that Brandmair was looking at French polish coats. I do not know if her samples had such coatings. I suspect that if she detected any shellac anywhere she would have said so.
Dan2 Posted August 2, 2017 Report Posted August 2, 2017 Unfortunately I'm not sure what a ground is actually. Does a mineral ground and a shellac ground perform the same function? Can a shellac be used as a ground and a sealer? With my first violin I used dewaxed shellac (ground/sealer?) and then varnished over the top of it. It doesn't look great actually. The light flames of the maple do not appear as brilliant as I have seen on professional instruments. On my second violin I am planning to use glair (as a ground/sealer?) and then oil varnish over the top.
Michael.N. Posted August 2, 2017 Report Posted August 2, 2017 I haven't found glair to be any better than shellac, at least not in an optical sense. Try them both side by side on an off cut.
sandman Posted August 4, 2017 Author Report Posted August 4, 2017 On 8/2/2017 at 11:20 AM, Mike Spencer said: Sandman is this your first instrument that you are getting ready to varnish? If it is then I'd suggest going with something that is easy like the gelatin size or shellac. It will work just fine and you won't have to drive yourself crazy with all the possibilities. Thank you. That is reassuring. It is actually my eighth instrument, all violins. The learning curve is still quite steep but I have managed to learn a few things. THe varnish/ground/primer/polish/etc mystery still has me confused. For every piece I read to answer a question I just get more questions. But this forum should be a real help. Thanks for your input!
sandman Posted August 4, 2017 Author Report Posted August 4, 2017 On 8/2/2017 at 3:05 PM, ctanzio said: I've used diluted dewaxed shellac as a ground under oil varnishes. Does a great job of sealing the wood. If you get inconsistent coloring then the mixture is not dilute enough. Make sure it is truly dewaxed shellac to get the highest clarity. Oil varnishes tend to want to form a "mechanical" bond to a surface, so you might have to gently sand the shellac coat with around 600 grit before the first oil varnish coat. Alternatively, if you first applied a mineral ground, then a light coat of thin shellac to seal it will normally still allow enough bite for the oil varnish. Thank you! I have used shellac but mixed it quite thick from dry crystals. I will thin it out and try on some scrap..
Nick Allen Posted August 4, 2017 Report Posted August 4, 2017 I've found it so confusing too. I think mostly because any source of info you get, is from a different person/school of thought, and all of them have their own methods and order in which they do things.
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